Flow meters find application in several technical fields. The measurement of flow is particularly important in the oil and gas production, for example for determining the quantity of hydrocarbons extracted from a reservoir. Also, when injecting a medium into a well, such as during enhanced oil recovery, the measurement of flow is of importance. A particular challenge is the measurement of flow in a subsea environment, in which pressures in excess of hundred bars can prevail.
A subsea production system can for example comprise a single well or plural satellite wells, which can be connected to each other via flow lines. Furthermore, such flow lines are generally provided for transporting produced hydrocarbons to a floating vessel, such as a floating production storage and offloading vessel (FPSO), to an offshore platform, or, via a pipeline, to an onshore side. To ensure a reliable operation of such subsea production system, flow measurements are required at several locations, for example at the well heads, at joints of the pipes and the like. It is particularly desirable to provide flow measurements with high precision and high reliability.
Often, flow meters suffer from the drawback that the measurements cannot be provided with the same precision over the whole range of measurable flow rates. Generally, deviations from low flow rates to high flow rates within a certain percentage are accepted. Furthermore, flow meters in the subsea environment make generally use of sensors that are arranged at different locations in the respective production system. A topside control unit or control panel receives sensor readings, such as pressure and temperature, from different sensors and thus from different sources. The topside control panel then calculates the flow rate from the different measurement values received from the different sources.